If your app utilizes WebView
to display web content, you might want
to consider optimizing click behavior for the following reasons:
-
WebViewdoesn't support tabbed browsing . Clicking a link opens the content in the default web browser.
-
WebViewdoesn't support custom URL schemes which could be returned in ads if the click destination is to a separate app. For example, a Google Play click-through URL might usemarket://.
- Google Sign-in
and Facebook Sign-in
aren't
supported in
WebView.
This guide provides recommended steps to optimize the click behavior in mobile web views while preserving the web view content.
Prerequisites
- Complete the Set up the web view guide.
Implementation
Follow these steps to optimize the click behavior in your WebView
instance:
-
Override
shouldOverrideUrlLoading()on theWebViewClient. This method is called when a URL is about to be loaded in the currentWebView. -
Determine whether to override the behavior of the click URL.
The code example checks if the current domain is different than the target domain. This is just one approach as the criteria you use could vary.
-
Decide whether to open the URL in an external browser, Android Custom Tabs , or within the existing web view. This guide shows how to open URLs navigating away from the site by launching Android Custom Tabs.
Code example
First add the androidx.browser
dependency to your module-level build.gradle
file, typically app/build.gradle
. This is required for Custom Tabs:
dependencies
{
implementation
'
androidx
.
browser
:
browser
:
1.5.0
'
}
The following code snippet shows how to implement shouldOverrideUrlLoading()
:
Java
public
class
MainActivity
extends
AppCompatActivity
{
private
WebView
webView
;
protected
void
onCreate
(
Bundle
savedInstanceState
)
{
super
.
onCreate
(
savedInstanceState
);
// ... Register the WebView.
webView
=
new
WebView
(
this
);
WebSettings
webSettings
=
webView
.
getSettings
();
webSettings
.
setJavaScriptEnabled
(
true
);
webView
.
setWebViewClient
(
new
WebViewClient
()
{
// 1. Implement the web view click handler.
@Override
public
boolean
shouldOverrideUrlLoading
(
WebView
view
,
WebResourceRequest
request
)
{
// 2. Determine whether to override the behavior of the URL.
// If the target URL has no host and no scheme, return early.
if
(
request
.
getUrl
().
getHost
()
==
null
&&
request
.
getUrl
().
getScheme
()
==
null
)
{
return
false
;
}
// Handle custom URL schemes such as market:// by attempting to
// launch the corresponding application in a new intent.
if
(
!
request
.
getUrl
().
getScheme
().
equals
(
"http"
)
&&
!
request
.
getUrl
().
getScheme
().
equals
(
"https"
))
{
Intent
intent
=
new
Intent
(
Intent
.
ACTION_VIEW
,
request
.
getUrl
());
// If the URL cannot be opened, return early.
try
{
MainActivity
.
this
.
startActivity
(
intent
);
}
catch
(
ActivityNotFoundException
exception
)
{
Log
.
d
(
"TAG"
,
"Failed to load URL with scheme:"
+
request
.
getUrl
().
getScheme
());
}
return
true
;
}
String
currentDomain
;
// If the current URL's host cannot be found, return early.
try
{
currentDomain
=
new
URI
(
view
.
getUrl
()).
toURL
().
getHost
();
}
catch
(
URISyntaxException
|
MalformedURLException
exception
)
{
// Malformed URL.
return
false
;
}
String
targetDomain
=
request
.
getUrl
().
getHost
();
// If the current domain equals the target domain, the
// assumption is the user is not navigating away from
// the site. Reload the URL within the existing web view.
if
(
currentDomain
.
equals
(
targetDomain
))
{
return
false
;
}
// 3. User is navigating away from the site, open the URL in
// Custom Tabs to preserve the state of the web view.
CustomTabsIntent
intent
=
new
CustomTabsIntent
.
Builder
().
build
();
intent
.
launchUrl
(
MainActivity
.
this
,
request
.
getUrl
());
return
true
;
}
});
}
}
Kotlin
class
MainActivity
:
AppCompatActivity
()
{
private
lateinit
var
webView
:
WebView
override
fun
onCreate
(
savedInstanceState
:
Bundle?)
{
super
.
onCreate
(
savedInstanceState
)
// ... Register the WebView.
webView
.
webViewClient
=
object
:
WebViewClient
()
{
// 1. Implement the web view click handler.
override
fun
shouldOverrideUrlLoading
(
view
:
WebView?,
request
:
WebResourceRequest?
):
Boolean
{
// 2. Determine whether to override the behavior of the URL.
// If the target URL has no host and no scheme, return early.
if
(
request
?.
url
?.
host
==
null
&&
request
.
url
.
scheme
==
null
)
{
return
false
}
val
currentDomain
=
URI
(
view
?.
url
).
toURL
().
host
// Handle custom URL schemes such as market:// by attempting to
// launch the corresponding application in a new intent.
if
(
!
request
.
url
.
scheme
.
equals
(
"http"
)
&&
!
request
.
url
.
scheme
.
equals
(
"https"
))
{
val
intent
=
Intent
(
Intent
.
ACTION_VIEW
,
request
.
url
)
// If the URL cannot be opened, return early.
try
{
this
@MainActivity.startActivity
(
intent
)
}
catch
(
exception
:
ActivityNotFoundException
)
{
Log
.
d
(
"TAG"
,
"Failed to load URL with scheme:
${
request
.
url
.
scheme
}
"
)
}
return
true
}
val
targetDomain
=
request
.
url
.
host
// If the current domain equals the target domain, the
// assumption is the user is not navigating away from
// the site. Reload the URL within the existing web view.
if
(
currentDomain
.
equals
(
targetDomain
))
{
return
false
}
// 3. User is navigating away from the site, open the URL in
// Custom Tabs to preserve the state of the web view.
val
customTabsIntent
=
CustomTabsIntent
.
Builder
().
build
()
customTabsIntent
.
launchUrl
(
this
@MainActivity
,
request
.
url
)
return
true
}
}
}
}
Test your page navigation
To test your page navigation changes, load
https://google.github.io/webview-ads/test/#click-behavior-tests
into your web view. Click each of the different link types to see how they behave in your app.
Here are some things to check:
- Each link opens the intended URL.
- When returning to the app, the test page's counter doesn't reset to zero to validate the page state was preserved.
